Generally, reactions relating genes including synthesis of cDNA from mRNA, amplification of DNA and the like are often conducted with a small volume and plural kinds of paratactic reactions. In such cases, in general, for example, a ninety-six well array, a three hundred and eighty-four well array or another micro well array is used, an array in which each well contains a reaction solution or a washing solution is prepared, and after completing reaction or washing operation the solution is transferred to the next well by means of a pipette, thereby the solution is subject to the next treatment. There is a situation that a robot is used to perform those treatments and operations conducted in routine.
However, even when a robot is used, a pipette which had been used for transferring a solution needs to be washed or replaced every time for using in next operation, and such operations are very troublesome.
It has been reported that instead of a pipette magnetic beads are employed and a sample immobilized on the magnetic beads is picked up and transferred by means of a magnet (for, example, JP Tokuhyo 2007-504835, Patent Document 1). However, when the micro well array mentioned above is used, a magnet for transferring is moved closer to the well from upside and in some case it needs to be immersed into a solution in the well. The magnet immersed into the solution needs to be washed before the next step. Also, the magnet needs to be demagnetizable in order to release the magnetic beads after the magnet is moved to the next step.
The non-patent publication 1 describes a RT-PCR reaction method using magnetic beads. In the method of the publication, a reaction at room temperature is carried out with adding 1 part of oil to 100 parts of a reaction solution, thereby the solution is covered with an oil membrane to avoid evaporation and the like.
Patent Document 1: Japanese Laid open patent publication Tokuhyou 2007-504835
Non-patent publication 1: Juergen Pipper, Masafumi Inoue, Lisa F-P Ng, Pavel Neuzil, Yi Zhang & Lukas Novak, NATURE MEDICINE VOLUME 13 NUMBER 10 October 2007 pp 1259-1263